The present invention relates to flat panel color displays having internal envelope support members and particularly to such a screen in which the color emitting phosphors are arranged to provide additional room for concealing the contact area between the internal support members and the screen.
There has been developed a flat panel display which includes an evacuated envelope having spaced, parallel, substantially flat front and back walls and a plurality of spaced, substantially parallel support walls extending between and substantially perpendicular to the front and back walls. One function of the support walls is to provide internal support for the front and back walls against the external atmospheric pressure. The display includes means for generating electrons and directing beams of the electrons against a phosphor screen on the inner surface of the front wall to achieve a visual display. One type of flat panel display which includes such a structure is shown and described in U.S. Pat. No. 4,001,620 to John G. Endriz, issued Jan. 4, 1977, entitled "Modulation Mask For An Image Display Device," and in the copending application for Letters Patent of John G. Endriz et al, Ser. No. 672,122, filed Mar. 31, 1976, entitled "Parallel Vane Structure For A Flat Display Device." Another type of flat panel display which uses such a construction is shown and described in the copending application for Letters Patent of Thomas O. Stanley, Ser. No. 607,492, filed Aug. 25, 1975, entitled "Flat Electron Beam Addressed Device," now U.S. Pat. No. 4,031,427, issued June 21, 1977.
In general, a phosphor screen for a color display includes a mosaic of phosphor bodies which when excited by electrons emit light of different colors, e.g. red, green and blue, arranged across the screen in a regular repetitive array. The phosphor bodies may, for example be circular areas of the phosphors or parallel stripes of the phosphors. A problem with the display devices of the above-identified construction is that the contact between the support walls and the front wall provides interruptions in the phosphor screen which can interfere with the visual display, e.g. provide undesirable visible lines across the display. Therefore, it would be desirable to have a phosphor pattern for a color display which would hide the support walls yet not interfere with the appearance of the visual display, i.e. without decreasing the resolution of the display.